Abdominal exercise machine



FIG. 1 is front perspective view of abdominal exercise machine of the subject invention;

FIG. 2 is a left side view thereof;

FIG. 3 is a right side view thereof;

FIG. 4 is a front view thereof;

FIG. 5 is a back view thereof; and,

FIG. 6 is a top view thereof. 

The ornamental design for an abdominal exercise machine, as shown. 